/*
 * Copyright 2009 XueSong Guo.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package cn.webwheel.database.types;

import java.io.CharArrayReader;
import java.io.CharArrayWriter;
import java.io.IOException;
import java.io.Reader;

/**
 * type for {@link java.sql.PreparedStatement#setCharacterStream(int, java.io.Reader, int)} and {@link java.sql.ResultSet#getCharacterStream(int)}
 */
public class CharacterStream extends CharArrayReader {

    public static CharacterStream valueOf(Reader reader) throws IOException {
        if(reader==null) return null;
        return new CharacterStream(reader);
    }

    public CharacterStream(Reader reader) throws IOException {
        super(new char[0]);
        CharArrayWriter caw = new CharArrayWriter();
        char[] buf = new char[1024];
        int rd;
        while ((rd = reader.read(buf)) != -1) {
            caw.write(buf, 0, rd);
        }
        reader.close();
        this.buf = caw.toCharArray();
        this.count = this.buf.length;
    }

    public int available() {
        return count - pos;
    }
}
